NOW, A CONTEST FOR MAYOR OF CHICAGO

By DIRK JOHNSON, Special to the New York Times

Published: April 7, 1987

CHICAGO, April 6—
Just as Mayor Harold Washington appeared to be coasting easily toward re-election here Tuesday in a crowded field, the sudden withdrawal of a major challenger has put the race on an uncertain turn.

In a move that surprised even veterans of Chicago politics, the Cook County tax assessor, Thomas C. Hynes, a Democrat who was running for mayor on a third-party slate, quit the campaign on Sunday, saying that opposition to Mr. Washington was being unwisely divided.

''The future of Chicago is on the line,'' Mr. Hynes said, urging his supporters to continute to work to defeat Mayor Washington. 'We've Got a Horse Race Now'

The race now focuses on Mr. Washington and Edward R. Vrdolyak, the Democratic county chairman, who has led the often hostile opposition to the Mayor in the last four years.

''We've got a horse race now,'' said Roman Pucinski, an alderman who opposes the Mayor's re-election.

A third candidate, Donald G. Haider, a former Democrat, is running as the nominee for the Republican Party, which has not won a mayoral election here in more than 60 years.

Although racial antagonism has played much less of a role in this campaign than in 1983, Mr. Washington's challengers, who are white, have stressed that a divided white vote would insure re-election for the Mayor, who is black.

''Don't vote for me because I'm white,'' said Mr. Vrdolyak, who has sought in the campaign to soften his combative image. ''Vote for me because I'm the best candidate.''

Blacks account for 44 percent of the registered electorate here, and Mr. Washington is expected to win more than 95 percent of their vote. The Mayor campaigned vigorously in black neighborhoods today, cautioning his supporters against complacency. 'The Great Showdown'

''Tomorrow is the great showdown -Washington versus Vrdolyak,'' the Mayor roared into a bullhorn today outside the huge Cabrini-Green public housing complex on the Near North Side. ''Everybody must come out tomorrow.''

Public opinion polls have showed Mayor Washington leading his opponents by a wide margin. In the most recent survey, a WBBM/CBS telephone poll April 1-3 of 551 registered voters, Mr. Washington was favored by 53 percent; Mr. Vrdloyak, 16 percent; Mr. Hynes, 11 percent, and Mr. Haider, 5 percent. The poll had a margin of sampling error of plus or minus four percentage points.

With the withdrawal of Mr. Hynes, backers of Mr. Vrdolyak predicted that opposition to the Mayor would consolidate behind their candidate and that white voters, believing that Mr. Washington can now be defeated, would go to the polls in record numbers.

But Mr. Washington's camp contends that the narrowed field will electrify the black vote and that many of Mr. Hynes's supporters will now back the Mayor. Rather than win 52 or 53 percent of the vote, they say, Mr. Washington will now get closer to 60 percent. Wants to Be Mayor for 20 Years

Mayor Washington, a 64-year-old former Congressman who began his political career as a precinct worker for the Democratic machine he would later condemn, seeks to become the first Mayor to win re-election here since Richard J. Daley won a fifth term in 1975.

Mr. Washington, who often states a desire to remain as Mayor for 20 years, has indicated that he intends to strengthen his grasp on the local Democratic Party in his next term.

Mr. Vrdolyak, a 49-year-old millionaire lawyer who was reared upstairs from his immigrant father's saloon on Chicago's rugged Southeast Side, spent much of his campaign in a battle with Mr. Hynes. It appeared to be a contest for second place that pundits dubbed ''the race for the silver medal.''

Mr. Hynes, the leading votegetter in Cook County elections last November, entered the race with a host of endorsements that included support from Richard M. Daley, the late Mayor's son, who is now the county prosecutor. Mr. Hynes offered himself as the ''unity'' candidate. An Exchange of Assertions

But Mr. Vrdolyak issued contentions that the assessor had used his influence to steer city contracts to his law firm, where he was receiving a part-time salary in excess of $90,000 a year.

In turn, Mr. Hynes said he had ''heard'' that Mr. Vrdolyak had been meeting with the reputed boss of the crime syndicate here and was receiving ''encouragement'' for his candidacy. Mr. Vrdolyak filed suit against The Chicago Sun-Times after it published that assertion, and he challenged Mr. Hynes to offer proof of the meeting. Mr. Hynes declined to explain the basis for his assertion, and the incident seemed ultimately to harm his candidacy more than Mr. Vrdolyak's.

The final blow to Mr. Hynes's candidacy came in last week, when polls showed that his performance in a debate was judged the poorest among the candidates. He abandoned the campaign, some of his supporters acknowledged privately, because he did not want to finish third and be tagged a ''spoiler,'' blamed for helping re-elect Mr. Washington.

Mr. Vrdolyak, conversely, was praised even by some critics for his debate performance, and his support blossomed.